I tried so hard to make my classes paperless, but, as an English teacher, the most difficult to solve was correcting/editing papers. This tool standardized the process a bit, which meant I at least didn't have to explain every mark I made on the paper. However, I never found a way to make the process go as fast as paper.
All I did for this download is create standard editor's marks for an online document. As of the time I had created this, no other version existed. There's nothing too clever about it: 7 grammatical highlight colors. An explanation of the comment function, A separate color for quotes to be highlighted--use this when you want students to show they used quotes in the paper.
This could be a really useful tool if you have a lot of time to grade and your students are going to bother to read what you've done to their papers. Grading papers online normally took me twice as long as the ones I got printed out, but once done, those papers remained for students to see, rather than ending up in the recycling bin.
I'd heard other teachers say Turnitin had some online paper grading tools that worked, so maybe check that out. Pricey. Or download this and male a few adjustments to suit your grading style.
If you're one of those admins who likes to mandate new practices on teachers, this might be a good one for you, especially if you have some kind of paper printing crisis at school. Just be aware that your teachers might not all like taking more time to grade papers, and you might have to end the ridiculous mandate that says papers need to be graded within a week.
Honestly, the best use is in a writing center or tutoring center. Social studies and world languages might get a decent use of it, too.
Link to Google Doc. I always copied and pasted entire document into student document so that they could see what my highlights meant. I'm sure it was potentially very useful.